michaelmas exam

Question 1

Light Microscope

Answer 1

1. they use a light source
2. alive specimen
3. uses lenses (objective and eyepiece)
4. Lower magnification
5. Magnification = 400= objective x eyepiece
6. Lower resolution
7. larger sub cellular structures
8. cheaper

Question 2

Electron microscope

Answer 2

1. requires computers and lots of space
2. Can only use dead samples
3. fires electrons at the sample
4. higher resolution
5. higher magnification = 1,000,000
6. very expensive

Question 3

PLANT CELL

1. chloroplasts
2. cytoplasm
3. cell wall
4. cell membrane
5. mitochondria
6. nucleus
7. vacuole

Answer 3

ANIMAL CELL

1. cytoplasm
2. Mitochondria
3. Nucleus
4. cell membrane

Question 4

what are the differences between animal and plant cells

Answer 4

plant cells have vacuoles, cell walls and chloroplasts

Question 5

what are eukaryotic cells

Answer 5

eukaryotic cells are cells that contain a nucleus

Question 6

what are the 7 things living cells need/ do

Answer 6

movement
respiration
sensitivity
growth
reproduce
excretion
nutrient

Question 7

what are the roles of the nucleus

Answer 7

1. controls the activities of the cell
2. contains deoxyreboneucleic acid
3. The DNA is organised into chromosomes

Question 8

what are the roles of the cell membrane

Answer 8

it controls the passage of substances into and out of the cell.

Question 9

what is the role of the cytoplasm

Answer 9

its where most chemical reactions occur

Question 10

Vacuoles

Answer 10

surrounded by a membrane
liquid called sap
vacuoles are permanent structures in plants

Question 11

when do cells divide

Answer 11

cells divide when the body either need to grow, replace or repair damaged tissue. It also happens during asexual reproduction

Question 12

where are chromosomes found

Answer 12

in the nucleus

Question 13

what are chromosomes made from

Answer 13

chromosomes are made from DNA

Question 14

how many chromosomes does the human body contain

Answer 14

the human body contains 23 chromosomes

Question 15

how are new cells made

Answer 15

to make new cells the original cell has to divide this is called the cell cycle:

1. DNA replicates to form 2 new copies. The cells grow grow and copies internal structures
2. One set of chromosomes is pulled to each end of the cell. The nucleus also divides
3. the cytoplasm and cell membrane divide into two identical cells

Question 16

what are daughter cells

Answer 16

daughter cells are the outcome of mitosis, they come in pairs

Question 17

how many chromosomes will a pair of daughter cells have

Answer 17

46= 23 x 2

Question 18

what is a prokaryotic cell

Answer 18

a cell without a nucleus

Question 19

how are cancer cells made

Answer 19

usually cells divide at certain times, sometimes this control stops and cells divide uncontrollably. This is cancer.

Question 20

what does cancer create

Answer 20

cancer often results in tumours

Question 21

what is a tumour

Answer 21

a tumour is a group of cells that have grown out of control, they are usually quite solid.

Question 22

what are the chemicals that cause cancer called

Answer 22

carcinogens

Question 23

what are stem cells

Answer 23

cells that can differentiate to become any cell in the body

Question 24

what makes a cell a specialised cell

Answer 24

specialised cells have developed structural adaptions that enable them to carry out their functions.

Question 25

name 2 adaptions for a sperm cell

Answer 25

1. Tail for movement
2. mitochondria for energy
3. nucleus carries 23 chromosomes

Question 26

name 2 adaptions for neurons

Answer 26

1. branches to connect with the muscle
2. extensions to communicate
3. fatty covering